The present invention relates to a socket for an electrical part such as semiconductor device (called hereunder xe2x80x9cIC packagexe2x80x9d) for detachably holding the electrical part, and more particularly, to a socket for an electrical part improved in structure of a contact pin which is contacted to or separated from a terminal of the electrical part.
As such socket for an electrical part, prior art provides an IC socket for detachably holding an IC package as an electrical part such as disclosed in Japanese Utility Model Publication No. HEI 6-44050.
In the IC socket of this prior art, as shown in FIGS. 11A and 11B, a contact pin 1 is formed with a pair of clamping pieces la to which contact portions lb contacting to or separating from a connection pin P of the IC package are formed, and press (pressed) portions, which are pressed by a cam portion 3a of a movable plate 3, are also formed to the clamping pieces la of the contact pin 1.
The cam portion 3a is inserted into a space between a pair of press portions 1c, and as shown in FIG. 11A, when the movable plate 3, to which the cam portion 3a is formed, is moved downward in the shown state, the paired press portions 1c are widened. Under this state, the connection pin P is inserted into the paired contact portions 1b through an insertion hole 4a formed to a cover 4.
With reference to FIG. 11B, then, when the movable plate 3 is moved upward, the cam portion 3a is also moved upward to thereby clamp the connection pin between the paired contact portions 1b and the electrical connection therebetween is hence established.
According to the structure mentioned above, the IC package can be mounted or dismounted, after arranging the IC package, only by moving the movable plate 3 in the vertical direction (upward or downward) without requiring insertion or draw-out force, thus improving a working efficiency.
In such prior art structure, the connection pin P is clamped between the contact portions 1b of the paired clamping pieces 1a of the contact pin 1 so as to establish the electrical connection therebetween. However, this structure is not provided with a clamping structure for attaining a wiping effect, and accordingly, a good stability in the contacting condition could not be expected.
An object of the present invention is to substantially eliminate defects or drawbacks encountered in the prior art mentioned above and to provide a socket for an electrical part capable of attaining a wiping effect and hence improving a contact stability at a time when a contact pin is contacted to a terminal.
This and other objects can be achieved according to the present invention by providing a socket for an electrical part having a socket body in which the socket body has a mount surface portion on which an electrical part is mounted, a plurality of contact pins are disposed to the socket body so as to be contacted to or separated from terminals of the electrical part and a movable plate is disposed to the socket body to be movable and in which when the movable plate is moved, contact portions of each of the contact pins are displaced so as to be contacted to or separated from the terminal of the electrical part,
wherein each of the contact pins is formed with an elastic piece having an end portion to which the contact portion is formed, the contact portion being contacted to a side surface portion of the terminal to thereby establish an electrical connection therebetween and the contact portion being formed with an inclining surface inclining, in a plan view in a use of the socket, with respect to a direction normal to the displacement direction of the contact portion.
In preferred embodiments, the contact pin is formed with a pair of elastic pieces having end portions to which contact portions are formed, respectively, between which the terminal is clamped for electrical connection therebeween, at least one of the contact portions being formed with an inclining surface inclining, in a plan view in a use of the socket, with respect to the direction normal to the displacement direction of the contact portion.
The contact pin may be formed with a pair of elastic pieces having end portions to which contact portions are formed, respectively, between which the terminal is clamped for electrical connection therebetween, the contact portions being formed with inclining surfaces inclining, in a plan view in a use of the socket, with respect to the direction normal to the displacement direction of the contact portion, the inclining surfaces of the respective contact portions being opposed substantially in parallel to each other.
The contact portion is formed with an orthogonal surface continuous to the inclining surface, the orthogonal surface being disposed along, in a plan view in a use of the socket, a direction normal to the displacement direction of the contact portion. The contact portion may be further provided with another inclining surface so as to provide a V-shaped groove, in a plan view in a use of the socket, between the former inclining surface and the other inclining surface.
In a more structural aspect, there is provided a socket for an electrical part comprising:
a socket body having a mount portion on which an electrical part is mounted, the electrical part having terminals;
a number of contact pins arranged to the socket body and adapted to be contacted to or separated from the terminals of the electrical part, respectively; and
a movable plate disposed to the socket body so as to be movable with respect to the socket body, each of the contact pins having an elastic piece formed at a front end portion thereof with a contact portion, the contact portion being displaced in accordance with the movement of the movable plate so as to contact to the terminal of the electrical part thereby being electrically connected thereto, and each of the contact portions being formed with an inclining surface inclining, in a plan view in a usable state of the socket, with respect to a direction normal to a direction of the displacement of the contact portion.
According to the structures and characters of the present invention mentioned above, the following functions and advantageous effects will be attained.
The contact portions of each of the contact pins are formed with inclining surfaces inclining, in a plan view in the use of the socket, with respect to a direction normal to the displacement direction thereof, so that the good wiping effect can be achieved by the simple structure of the contact pins as well as the stable electrical connection between the contact pins of the socket body and the terminals of the electrical part.
In the arrangement in which the contact portions of the paired elastic pieces of the contact pin have inclining surfaces opposed substantially in parallel to each other in a direction normal to the displacement direction, the centering function to the terminal can be enhanced.
Furthermore, in the arrangement in which the orthogonal surface is formed continuous to the inclining surface in a direction normal to the displacement direction of the contact portion, the strength of the contact portion can be ensured. Moreover, the width of the contact portion can be properly kept, and even if the terminal and the contact portion are slightly shifted in the positional relation thereof, good contacting condition can be ensured and the biting of the contact portions to the terminal can be also prevented.
In the arrangement in which the contact portions are each formed with two inclining surfaces so as to provide V-shape groove in a plan view in the use of the socket, the terminal is fitted in the V-shaped grooves of both the contact portions, thus keeping the well holding condition of the terminal. Then, when one of the inclining surface is slid along the side surface of the terminal, the terminal is well fitted into the V-shaped grooves, so that the sliding motion is stopped and the contact portions are hence not come off from the terminal.
The nature and further characteristic features of the present invention will be made more clear from the following descriptions made with reference to the accompanying drawings.